Antenna



g- 6 R. E. DILLON ETI'AL ANTENNA Filed May 31, 1946 INVENTORS ROBERT E. DILLON LEONARD .J. EYGES HENRY J. RIBLET ATTORNEY ANTENNA Robert E. Dillon, Maiden, and Leonard J. Eyges, Chelsea, Mass, and Henry .l. Riblet, Erie, Pa, assignors, by mesne assignments, to the United States of America as represented by the Secretary of the Navy Application May 31, 1946, Serial No. 673,230 7 Claims. (Cl. 343-485) This invention relates to high frequency antennas and more particularly to high frequency horn antennas to produce narrow beam widths with relatively small antenna dimensions.

The more common types of high frequency directional antennas use either parabaloid horn antennas or reflectors, or dielectric rods of polystyrene. In dielectric rods used to guide high frequency energy and form a directive beam of radiation, the directivity is a function of the length of the rod; the longer it is, the sharper the beam. When parabolic horns or reflectors are used to form directive beams, the larger the aperture, the sharper the beam. In this embodiment of the invention a compact high frequency antenna is proposed that is intermediate between polystyrene rods and parabolic horns in that both the length and aperture size contribute to the directivity. For a given beam width it is shorter than the polystyrene rod that would give the same beam width and the aperture is smaller than the corresponding parabolic horn or reflector.

A primary object of this invention is to provide a high frequency horn antenna having a narrow beam width.

Another object of this invention is to provide a compact high frequency horn antenna having a narrow beam width.

A further object is to provide a compact high frequency horn antenna having a narrow beam width symmetrical about an axial line for scanning purposes.

These and other objects will be apparent from the following description when taken with theaccompanyi-ng drawings in which:

Fig. l is a top plan view of one form and Fig. 2 is a side elevation sectional view of the embodimeut of Fig. 1, taken in partial section on the line 'II II in Fig. 1.

In the drawings and more particularly Fig. 2, a centerdrilled polystyrene cylinder 111 is fitted into one end of circular wave guide 1'2. The aperture in center-drilled polystyrene cylinder 11 is closed by brass disc 13. The other end of circular wave guide 12 is fitted with adjustable piston 14 with adjustments in its position made by knob 15 and shaft 16. Adjustable probe 17 and fitting 18 are used to introduce high frequency energy to circular wave guide 12. in the operation of this embodiment of the invention, the high frequency energy introduced in the waveguide by probe 17 impinges upon the end of polystyrene cylinder 111 causing it to radiate. Brass disk :13 is located in the aperture of polystyrene cylinder Ll forming an electrical short so that only polystyrene cylinder 11 radiates high frequency energy. Adjustable piston 14 is placed so that all of the energy irom probe 17 is passed to the end of waveguide 12 having polystyrene cyliuder v11 tit-ted therein. This energy that is passed to polystyrene cylinder 11 is radiated as a beam of high frequency energy, of narrow width, the beam width depending upon the dimensions of the polystyrene cylinder.

If it is desired, brass disk .13 may be omitted from the of the invention;

hired States atent 2 aperture in polystyrene cylinder 11. If the aperture in polystyrene cylinder 11 is left open, the length of cylinder 11 must be chosen so that radiation from polystyrene cylinder 11 and that from the center of the aperture are in phase.

The invention described in the foregoing specification need not be limited to the details shown, which are considered to be illustrative of form the invention may take. The scope of the invention is defined by the appended claims.

What is claimed is: r

1. A compact high frequency antenna horn having a small beam width comprising, a circular wave guide, a source of high frequency energy, a probe to couple said high frequency energy into said circular wave guide, means at one end of said wave guide to cause all of said high frequency energy to pass to the other end of said circular wave guide, a center-drilled polystyrene cylinder partially inserted in said other end of said circular WZtVfl guide, the protruding end of said center-drilled polystyrene being a radiator of said high frequency energy impinging on the portion of said polystyrene cylinder inserted in said circular wave guide, and means within said cylinder to prevent radiation from occurring from the aperture of said center-drilled polystyrene cylinder.

2. A compact high frequency horn antenna having a narrow bandwidth, symmetrical about an axial line comprising, a circular wave guide, a source of high frequency energy, a probe to couple said high frequency energy into said circular wave glide, an adjustable piston in one end of said wave guide, said adjustable piston being placed in said circular wave guide so that all of said high frequency energy is directed toward the other end of said circular wave guide, a =center-drilled polystyrene cylinder, one end of said polystyrene cylinder being inserted into the open end of said circular wave guide, said high frequency energy in said circular Wave guide impinging on said polystyrene cylinder and causing the protruding end of said polystyrene cylinder to radiate said high frequency energy, and means within said cylinder to prevent the aperture in said polystyrene cylinder rrom radiating high frequency energy.

3. A compact high frequency antenna horn having a narrow "beam width symmetrical about an axial line comprising, a circular wave guide, a source of high frequency energy, a probe to couple said high frequency energy into said Wave guide, an adjustable piston in one end of said Wave guide, said piston being adjustable to cause all of said high frequency energy to pass toward the other end of said wave guide, a center-drilled polystyrene cylinder, one end of said cylinder being introduced into the open end of said wave guide, said high frequency energy in said wave guide impinging on said polystyrene cylinder causing the protruding end of said polystyrene cylinder to radiate said high frequency energy, and a brass disk located in the aperture of said center-drilled polystyrene cylinder to prevent high frequency energy from radiating from said aperture.

4. An antenna comprising, :a section of circular wave guide substantially shorted at one end thereof, a tuning device disposed at the other end thereof, means for introducing energy into said wave guide, and a radiating dielectrio member partially inserted at said substantially shorted end for radiating energy introduced into said circular wave guide.

5. An antenna comprising, a circular wave guide, a hollow cylindrical dielectric member partially inserted in said circular wave guide, means for introducing high frequency energy into said circular wave guide, a shorting structure disposed across the opening of said hollow dielectric substantially at the point of insertion of said hollow cylindrical dielectric member.

6. An antenna comprising, a section of wave guide, a tuning device inserted at one end thereof, means for introducing energy into said wave guide, a hollow dielectric member inserted at the other end there-of for radiating energy introduced into said wave guide, and a conductive disk inserted Within said hollow dielectric member 'substantially at said other end of said wave guide.

7. An antenna comprising a length of circular wave guide, an adjustable piston inserted at one end of said wave guide, an adjustable probe inserted radially in a wall of said wave guide, a hollow cylindrical dielectric member partially inserted at the other end of said wave guide, and a metal disk disposed across the opening of said hollow dielectric member substantially at said other end of said wave guide, said dielectric member being a 15 2,5

radiator of energy introduced into said wave guide by said adjustable probe.

References Cited in the file of this patent UNITED STATES PATENTS 2,129,711 Southw-or-th Sept. 13,1938 2,283,568 0111 May '19, 1942 2,304,540 Oassen Dec. 8,1942 2,307,012 Barrow Jan. 5,1943 2,343,531 Buchholz Mar. 7, 1944 2,416,698 King Mar. 4, 1947 2,425,336 Mueller Aug. 12, 1947 2,460,401 Southworth Feb. 1, 1949 2,473,446 Riblet June 14, 1949 Simpson June 5, 1951 

1. A COMPACT HIGH FREQUENCY ANTENNA HORN HAVING A SMALL BEAM WIDTH COMPRISING, A CIRCULAR WAVE GUIDE, A SOURCE OF HIGH FREQUENCY ENERGY, A PROBE TO COUPLE SAID HIGH FREQUENCY ENERGY INTO SAID CIRCULAR WAVE GUIDE, MEANS AT ONE END OF SAID WAVE GUIDE TO CAUSE ALL OF SAID HIGH FREQUENCY ENERGY TO PASS TO THE OTHER END OF SAID CIRCULAR WAVE GUIDE, A CENTER-DRILLED POLYSTYENE CYLINDER PARTIALLY INSERTED IN SAID OTHER END OF SAID CIRCULAR WAVE GUIDE, THE PROTRUDING END OF SAID CENTER-DRILLED POLYSTYRENE BEING A RADIATOR OF SAID HIGH FREQUENCY ENERGY IM- 